The present invention relates to a stator casing for air-cooled electrical machines, comprising a sheet metal jacket to be placed on the stator core which has a plurality of shaped-on, axially extending, radially projecting and peripherally spaced cooling ribs.
Such a casing is already known from Swiss Pat. No. 92,809 but in this design it has been found that the sheet metal jacket used therein must be made slightly axially longer than the stator core. The jacket thus extends axially, on either side a casing part in addition to the non-supporting sheet metal jacket, which only serves a cooling function.
With the arrival of new technology in which the cast metal casing parts can be directly replaced by an extended sheet metal cooling rib jacket. The new jacket, however, has to be wholly or partly self-supporting, in addition to exercising its cooling function. Such constructions, for example Swiss Pat. No. 337,226 or West German Offenlegungsschrift No. 2,233,860 are connected by means of complicated and costly welds to the stator core surface in order to obtain the necessary surface termination or dissipation of heat and the transfer of forces.